1. Field of the Invention
The invention relates to a vehicle navigation system and the display method thereof and, more particularly, to a vehicle navigation system capable of displaying a corrected vehicle signing location on a screen, and the display correction method thereof.
2. Description of Related Art
FIG. 1 shows a typical vehicle with a navigation function. As shown in FIG. 1, the vehicle has a global position system (GPS) 81 and a navigation system 82. Typically, the GPS 81 can receive the signals of global positioning satellites in the space and accordingly compute current vehicle coordinates, at any time. The navigation system 82 has a microprocessor 821 to compare the current vehicle coordinates with a built-in e-map database 822 for finding the corresponding location on a map of the database 822 and displaying a sign, which is indicative of the vehicle, on the display 83. Thus, when driving, the driver can know the vehicle's location in real-time.
However, due to a certain inaccuracy, the GPS 81 often generates the condition of FIG. 2 in which a schematic map illustrates an incorrect display of a typical vehicle navigation system. As shown in FIG. 2, when a driver controls a vehicle on the road 220, for a normal condition, a sign 230 indicative of the vehicle is displayed on the road 220, as shown in the circle A. However, due to an error caused by the GPS 81, the microprocessor 821 compares the incorrect current vehicle coordinates with the built-in e-map database 822, and accordingly displays the sign 230, which is indicative of the vehicle, off the road 220, as shown in the circle B. Such an error causes the driver to increasingly doubt the road's condition and to reduce trust in the reliability of the vehicle navigation system. In addition, when the vehicle is driven in a tunnel, the signals of the GPS satellites 9 cannot be received. In this case, the computed value for the current vehicle coordinates is not accurate, and the microprocessor 821 accordingly has an incorrect comparison with the database 822 and displays the sign 230, which is indicative of the vehicle, at an incorrect position. Thus, an improvement on the typical vehicle navigation system is required.